United have bought a centre-back in each of the last two summers and currently have five defenders battling it out for just two positions: Chris Smalling, Eric Bailly, Phil Jones, Victor Lindelof and Marcos Rojo. That is without even mentioning youngster Axel Tuanzebe.

Also, the reality is United will have to pay at least a club-record fee for a defender to land their ideal target.

The club are looking at defenders aged between 23 and 29 who have played in the Premier League, Serie A, La Liga or the Bundesliga and are as comfortable with the ball at his feet as they are making a headed clearance.
Bailly is back en vogue [Photo: Courtesy]

But it will not be easy and one high-level source at United is well aware that some of those players under consideration 'are not possible and real'.

Mourinho, though, does not appear too sure United will get their man. Having already said that he had 'no idea' if United would make any further additions, following the signings of Fred, Diogo Dalot and Lee Grant, he dropped his biggest hint yet in his first pre-season line-up.

Smalling and Bailly, the centre-backs who did not go to the World Cup, started together.

While it is easy to read too much into that, Mourinho made a point of repeatedly pairing Smalling with Lindelof last summer as he knew both Jones and Bailly would be suspended for the Super Cup clash with Real Madrid.
Smalling played his way into the team last term [Photo: Courtesy]

Equally, a number of those defenders on United's radar played at the World Cup and may be lacking match sharpness by the time the window closes.

Regardless, with his latest gesture, Mourinho all but confirmed his back line for the first league game of the season against Leicester on August 10.

"Valencia, Smalling, Bailly and Shaw, they are probably the ones to start the season," he told MUTV.